RESUMEN
AIM: This study aims to identify new genes not described previously that may be relevant in the etiology or pathophysiology of patients with Hirschsprung disease (HD). This was done by identifying differences in gene expression between normal and abnormal segments of bowel in HD patients compared with controls. METHODS: Full-thickness colonic tissue samples were taken from HD patients, both from the diseased (Ds) and normal segment of the colon (Nr), and from controls (Ct). Samples were further dissected into mucosa (MUC) and muscle (MUS). RNA was extracted and analyzed on Affymetrix Gene Chip Human Gene 1.0 ST arrays. Statistical analyses using ANOVA with a fold change cut off of 2 was applied to detect a number of differentially expressed genes. Selected genes were revalidated by quantitative real-time reverse transcriptase polymerase chain reaction. RESULTS: Thirty-four samples (18 MUS and 16 MUC) were analyzed. MUC (1.64 ± 0.46 µg/mg) and MUS (0.83 ± 0.48 µg/mg) showed good RNA extraction yield and quality. Of the 24,987 filtered on expression genes, MUS showed 220 genes with expression difference of 2-fold, out of which 120 genes were significant with P ≤ .05. Similarly, MUC demonstrated 206 genes with 2-fold changes and 9 had P ≤ .05. Some genes showing differential expression between groups and therefore subject to further analysis were RELN, GAL, GAP43, NRSN1, and GABRG2. CONCLUSION: Analyzed data showed significant differences in expression of above sets of genes with up- and down-regulation, which has not been described before in HD and could have a role in pathogenesis of this condition.
Asunto(s)
Perfilación de la Expresión Génica , Enfermedad de Hirschsprung/genética , Moléculas de Adhesión Celular Neuronal/biosíntesis , Moléculas de Adhesión Celular Neuronal/genética , Colon/metabolismo , Proteínas de la Matriz Extracelular/biosíntesis , Proteínas de la Matriz Extracelular/genética , Femenino , Proteína GAP-43/biosíntesis , Proteína GAP-43/genética , Galanina/biosíntesis , Galanina/genética , Estudio de Asociación del Genoma Completo , Enfermedad de Hirschsprung/metabolismo , Humanos , Lactante , Mucosa Intestinal/metabolismo , Masculino , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , Músculo Liso/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de GABA-A/biosíntesis , Receptores de GABA-A/genética , Proteína Reelina , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Serina Endopeptidasas/biosíntesis , Serina Endopeptidasas/genéticaRESUMEN
Polycationic non-viral polymers are widely employed as delivery platforms of plasmid DNA, or of small interfering RNAs (siRNAs) for the induction of RNA interference (RNAi). Among those, poly(ethylene imine)s (PEIs) take a prominent position due to their relatively high efficacy; however, their biodistribution profiles upon systemic delivery and their toxicity pose limitations which can be addressed by the introduction of PEI modifications. In this paper, we systematically analyse physicochemical and biological properties of DNA and siRNA complexes prepared from a set of maltose-, maltotriose- or maltoheptaose-modified hyperbranched PEIs (termed (oligo-)maltose-modified PEIs; OM-PEIs). We show that pH-dependent charge densities of the OM-PEIs correlate with the structure and degree of grafting, and the length of the oligomaltose. Decreased zeta potentials of OM-PEI-based complexes and changes in the thermodynamics of DNA complex formation are observed, while the complex sizes are largely unaffected by maltose grafting and the presence of serum proteins. Furthermore, although complexation efficacies of siRNAs are not altered, complex stabilities are markedly increased in OM-PEI complexes. DNA complex uptake and transfection kinetics are slowed down upon maltose-grafting of the PEI which can be attributed to decreased zeta potentials, and alterations in the uptake mechanisms (clathrin-dependent/clathrin-independent endocytosis) are observed. Independent of the maltose architecture, DNA and siRNA complexes based on maltose-grafted PEI show considerably lower cytotoxicity as compared to PEI complexes. While maltose grafting generally leads to reduced in vitro transfection efficacies, this effect is less profound in some OM-PEI/siRNA complexes as compared to OM-PEI/DNA complexes. Importantly, upon their systemic application in vivo, OM-PEI/siRNA complexes show marked differences in the siRNA biodistribution profile with e.g. substantially decreased siRNA levels in the liver and increased siRNA levels in the muscle. Taken together, we demonstrate that OM-PEI complexes show structure-dependent physicochemical and biological properties and may represent promising, tailor-made platforms for the delivery of siRNAs, particularly for in vivo applications.
Asunto(s)
ADN , Portadores de Fármacos/química , Iminas/química , Maltosa/química , Polietilenos/química , ARN Interferente Pequeño , Trisacáridos/química , Técnicas de Cultivo de Célula , Línea Celular Tumoral , Supervivencia Celular , Fenómenos Químicos , ADN/administración & dosificación , ADN/genética , Citometría de Flujo , Humanos , Luciferasas/genética , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/genética , TransfecciónRESUMEN
The potential of two Rhodococcus strains for biotechnological vanillin production from ferulic acid and eugenol was investigated. Genome sequence data of Rhodococcus sp. I24 suggested a coenzyme A-dependent, non-beta-oxidative pathway for ferulic acid bioconversion, which involves feruloyl-CoA synthetase (Fcs), enoyl-CoA hydratase/aldolase (Ech), and vanillin dehydrogenase (Vdh). This pathway was proven for Rhodococcus opacus PD630 by physiological characterization of knockout mutants. However, expression and functional characterization of corresponding structural genes from I24 suggested that degradation of ferulic acid in this strain proceeds via a beta-oxidative pathway. The vanillin precursor eugenol facilitated growth of I24 but not of PD630. Coniferyl aldehyde was an intermediate of eugenol degradation by I24. Since the genome sequence of I24 is devoid of eugenol hydroxylase homologous genes (ehyAB), eugenol bioconversion is most probably initiated by a new step in this bacterium. To establish eugenol bioconversion in PD630, the vanillyl alcohol oxidase gene (vaoA) from Penicillium simplicissimum CBS 170.90 was expressed in PD630 together with coniferyl alcohol dehydrogenase (calA) and coniferyl aldehyde dehydrogenase (calB) genes from Pseudomonas sp. HR199. The recombinant strain converted eugenol to ferulic acid. The obtained data suggest that genetically engineered strains of I24 and PD630 are suitable candidates for vanillin production from eugenol.